John Gill Commentary Psalms 70:5

"But I am poor and needy; Make haste unto me, O God: Thou art my help and my deliverer; O Jehovah, make no tarrying." — Psalms 70:5 (ASV)

But I [am] poor and needy
In (Psalms 40:17) it follows, yet "the Lord thinketh on me"; instead of which it is here, (See Gill on Psalms 40:17);

make haste unto me, O God ;
which repeats for sense the same petition as in (Psalms 71:1) ;

you [are] my help and my deliverer; O Lord, make no tarrying ;
in (Psalms 40:17) it is, "O my God".