No man can do more than he has strength to do. There is an Aberdeenshire saying of similar import, "I can dee fat I dow: the men in the Mearns can dee nae mair."
A' the speed's no in the spurs.
A' the winning's in the first buying.
A' the wit o' the world's no in ae pow.
A'thing angers ye, and the cat breaks your heart.
A' things thrive at thrice.
A'thing wytes that no weel fares.
A thoughtless body's aye thrang.
A thrawn question should hae a thrawart answer.
A thread will tie an honest man better than a rope will do a rogue.