Thrift of time will repay you in afterlife, with a usury of profit beyond your most sanguine dreams; waste of it will make you dwindle, alike in intellectual and moral stature, beyond your darkest reckoning.
We should repay the favours of others by acts of kindness; so also should we return evil for evil in which there is no sin, for it is necessary to pay a wicked man in his own coin.