Ask thy purse what thou shouldst buy.

A purchase should be guided by the money available, rather than by desire alone. The purse stands for the buyer’s financial means.

The proverb advises restraint when weighing an expense: first consider what you can afford, then decide whether the purchase is sensible.

Use it to counsel someone who is considering a purchase beyond their budget, or as a reminder to check available funds before choosing among things to buy.