If you ask for money to tide you over, you are using a nautical term to reassure the lender that repayment is inevitable.
When a boat or ship wants to enter a river from the ocean at low tide, its way will be blocked by the accumulation of mud or sand that has been swept downstream and collected at the mouth of the river.
When the predictable tide rises and the obstacle is “tided over” the boat, like a borrower, can continue its progress.
If you’re short of cash why might you ask for a loan to “tide you over”?