A.T. Robertson Commentary Matthew 23:4

"Yea, they bind heavy burdens and grievous to be borne, and lay them on men`s shoulders; but they themselves will not move them with their finger." — Matthew 23:4 (ASV)

With their finger (τω δακτυλω αυτων). A picturesque proverb. They are taskmasters, not burden-bearers, not sympathetic helpers.