'Hand's' in the Bible

You have made my days no longer than a hand's measure; and my years are nothing in your eyes; truly, every man is but a breath. (Selah.)

And there was a wall on the outside of the house all round, and in the man's hand there was a measuring rod six cubits long by a cubit and a hand's measure: so he took the measure of the building from side to side, one rod; and from base to top, one rod.

And these are the measures of the altar in cubits: (the cubit being a cubit and a hand's measure;) its hollow base is a cubit high and a cubit wide, and it has an overhanging edge as wide as a hand-stretch all round it: