from ‘to claw the back of‘ (to flatter, fawn upon)
“…Yea, trouble not your self sir, ye may hauke and hunt, & take youre pleasure. As for the guiding of your kingdom and people, let vs alone with it.
These flattering clawbackes ar original rotes of all mischief…”
From: The Second Sermon of Maister Hughe Latimer, which be Preached before King Edward
By Hugh Latimer, 1549