Answer
Joshi Ji, regarding your question, you have asked for references from the Gita and similar scriptures. Therefore, I shall first provide you with some relevant verses concerning the mind, along with word-by-word analysis (padachchheda) and meanings. First, study and contemplate them. These verses will facilitate your reflection. After that, discussion will become easier.
Here are the relevant verses from the Gita on this subject:
Prajahati yada kaman sarvan Partha manogatan | Atmany evatmana tushtah sthita-prajnas tadochyate || 2:55 ||
Pra-jahati yada kaman sarvan, Partha, manah-gatan, Atmani eva atmana tushtah — sthita-prajnah tada uchyate.
Partha (O Partha)! yada (when) manah-gatan (situated in the mind) sarvan (all) kaman (desires) pra-jahati (abandons), atmana (by the Self) atmani (in the Self) eva (alone) tushtah (remains satisfied), tada (then) sthita-prajnah (a person of steady wisdom) uchyate (is said to be).
Meaning: When a person completely abandons all desires dwelling in the mind and remains satisfied within the Self by the Self alone — then, O Partha, that person is called sthitaprajna (one of steady wisdom).
Yatato hy api Kaunteya purushasya vipashchitah | Indriyani pramathini haranti prasabham manah || 2:60 ||
Yatatah hi api, Kaunteya, purushasya vi-pashchitah, Indriyani pra-mathini haranti prasabham manah.
Kaunteya (O son of Kunti, Arjuna)! hi (certainly) pramathini (turbulent, agitating) indriyani (the senses) yatatah (even while striving) api (even) vi-pashchitah (of the discerning) purushasya (person's) manah (mind) prasabham (forcibly) haranti (carry away).
Meaning: O Arjuna, the turbulent senses forcibly carry away the mind even of a discerning person who is striving for self-control!
Indriyanam hi charatam yan mano’nuvidhiyate | Tad asya harati prajnam vayur navam ivambhasi || 2:67 ||
Indriyanam hi charatam yat manah anu-vi-dhiyate, Tat asya harati prajnam, vayuh navam iva ambhasi.
hi (because) iva (just as) ambhasi (in the water) navam (a boat) vayuh (the wind) harati (carries away), charatam (of the wandering) indriyanam (senses, among the senses) manah (the mind) yat (whichever) anu-vi-dhiyate (follows after), tat (that) asya (of this person) prajnam (wisdom, intelligence) harati (carries away).
Meaning: Just as the wind carries away a boat on the water — forcibly sweeping it off in the wrong direction — so too, whichever wandering sense the mind attaches itself to, that sense carries away the person's wisdom, that is, sweeps it far from the goal.
Yas tv indriyani manasa niyamyarabhate’rjuna | Karmendriyaih karma-yogam asaktah sa vishishyate || 3:7 ||
Meaning: But, O Arjuna, the person who controls the senses by the mind, and without attachment engages the organs of action in Karma Yoga — that one is superior.
Indriyani mano buddhir asyadhishthanam uchyate | Etair vimohayaty esha jnanam avritya dehinam || 3:40 ||
Indriyani manah buddhih asya adhishthanam uchyate, Etaih vi-mohayati eshah jnanam avritya dehinam.
Indriyani (the senses) manah (the mind) buddhih (the intellect) asya (its, of this desire) adhishthanam (seat, abode) uchyate (are said to be). Eshah (this desire) etaih (through these — mind, intellect, senses) jnanam (knowledge) avritya (covering, veiling) dehinam (the embodied soul) vi-mohayati (deludes).
Meaning: The senses, mind, and intellect are said to be the dwelling places of this desire. Through these — mind, intellect, and senses — desire veils knowledge and deludes the embodied soul.
Indriyani parany ahur indriyebhyah param manah | Manasas tu para buddhir yo buddheh paratas tu sah || 3:42 ||
Indriyani parani ahuh indriyebhyah param manah, Manasah tu para buddhih yah buddheh paratah tu sah.
Indriyani (the senses) parani (superior) ahuh (are said to be). Indriyebhyah (than the senses) param (superior) manah (the mind). Manasah (than the mind) tu (indeed) para (superior) buddhih (the intellect). Tu (and) yah (that which) buddheh (than the intellect) paratah (superior) sah (that is the Atman).
Meaning: The senses are superior to the gross body. Superior to the senses is the mind. Superior even to the mind is the intellect. And that which is superior to the intellect is the Atman (the Self).
Evam buddheh param buddhva samstabhyatmanam atmana | Jahi shatrum maha-baho kama-rupam durasadam || 3:43 ||
Evam buddheh param buddhva sam-stabhya atmanam atmana, Jahi shatrum maha-baho kama-rupam duh-asadam.
Evam (thus) buddheh (than the intellect) param (the Supreme, the Self) buddhva (knowing), atmana (by the Self, i.e. the intellect) atmanam (oneself, i.e. the mind) sam-stabhya (steadying, restraining), maha-baho (O mighty-armed one) kama-rupam (in the form of desire) duh-asadam (hard to conquer) shatrum (enemy) jahi (slay, destroy).
Meaning: Thus knowing the pure Atman to be beyond the intellect, and steadying the mind through the intellect, O mighty-armed one, slay this formidable enemy in the form of desire.