From the origin of the wealth, not from the bank transfer. For an inheritance that means the deceased's estate documents, the grant, the distribution statement and the receiving account records. For registered account proceeds it means the account history, the source of the original contributions, and the tax treatment of the withdrawal.
Two sources, two complete chains
Each source of funds needs its own documented path, and combining them in a single account before the investment does not merge the analysis. An inheritance is evidenced by the estate: the will or the grant of administration, the estate accounts, the statement showing the distribution to this beneficiary, and the records of the money arriving in his account. Where the estate itself held assets that were sold, that sale may need explaining too.
Registered retirement funds are evidenced differently: the account statements over time, evidence of how the contributions were earned, which for a long career means employment and tax records, and the tax reporting of the withdrawal. Both chains then converge on the transfer into the enterprise. Where documents are held by a Canadian institution, requesting historical records takes weeks, so this work should start well before a project is chosen.
Gaps are better acknowledged and explained than papered over.