Difference between Have something in one’s hands and Have something on one’s hands

have something in one’s hands—

1. be in possession of smth.; have smth. in reserve:

• After paying the debt in full, with the accumulated interest, he still had in his hands about $1,000.

2. have complete control of smth.:

• I thought long and hard about how I could introduce you to the teachers who had my fate in their hands.

Note: The expression does not fully correlate in meaning with the phrase have something in hand—

1. have smth. under control:

• There was a little rioting, but the police soon had the situation in hand.

2. = have something in one’s hands 1:

• The money question had also to be gone into: what he still had in hand; what balance lay in the London bank.

have something on one’s hands—said of smth. remaining under one’s care as a burden or unwelcome responsibility:

• When the house is sold I will have the furniture on my hands.