Psalm 119:49 Remember the word to Your servant, upon which You have caused me to hope.
As if God needs reminding! Well, it is not for God that we lift up our prayers but for us and for others; so David’s prayer to ask God to not forget was really for his own benefit.
What God has said is a promise because He does not tell lies and He does not change, but we change and we make things difficult. So by lifting up this prayer it is as much a reminder to us to not forget that God has promised!
God gave us His Word so that we could have something to believe on and something to give us hope as we see His promises unfolding in our lives.
Take hold of those promises and keep reminding yourself!