Spend, and God will send; spare, and be bare.
Spilt ale is waur than water.
Spit in your loof and haud fast.
This means, simply, take a firm hold of a thing.
Spit on a stane and it will be wat at last.
Stable the steed, and put your wife to bed when there's night wark to do.
"'Am I no gaun to the ploy, then?' said Maggie, in a disappointed tone. 'And what for should ye?' said her lord and master; 'to dance a' night, I'se warrant, and no to be fit to walk your tae's-length the morn, and we have ten Scots miles afore us? Na, na. Stable the steed, and pit your wife to bed when there's night wark to do.'"—Redgauntlet.
Standers-by see mair than gamesters.
Staunin' dubs gather dirt.
"Standing pools gather filth."—English.