A bird in hand is worth two in the bush

पुस्तकस्था तु या विद्या
परहस्तगतं धनम् ।
कार्यकाले समुत्पन्ने
न सा विद्या न तद्धनम् ॥

- चाणक्यनीतिः

Knowledge residing in a book and money loaned to others; when in need, neither that knowledge nor that money is of any use.

A bird in hand is worth two in the bush.
Better to have it and not need it than to need it and not have it.