to pray, that is. Martyn Lloyd-Jones wrote the following to preachers, but I'm pretty sure every Christian needs to hear it. I know I do. I can't count how many times the Lord has brought to me an impulse to pray and I said "in a minute" (my wife is familiar with this line) or "after I email this very important email" or "later, when I'm not busy". The truth is, I will always be too "busy". If we don't pray when we feel the impulse, chances are we won't later. The impulse to pray is from God's Spirit in us. It is His kindness to us to remind us to do what He knows will be of great benefit to us, namely, to talk to Him. Let's not ignore the urge to pray, which is God's means of grace for us.
(h/t - Ordinary Pastor)
Above all — and this I regard as most important of all — always respond to every impulse to pray. The impulse to pray may come when you are reading or when you are battling with the text. I would make an absolute law of this — always obey such impulse.
Where does it come from? It is the work of the Holy Spirit; it is a part of the meaning of, 'Work out your salvation with fear and trembling. For it is God which worketh in you both to will and to do of his good pleasure' (Philippians 2:12–13).
This often leads to some of the most remarkable experiences in the life of the minister. So never resist, never postpone it, never push it aside because you are busy. Give yourself to it, yield to it; and you will find not only that you have not been wasting time with respect to the matter with which you are dealing, but that actually it has helped you greatly in that respect. You will experience an ease and a facility in understanding what you were reading, in thinking, in ordering matter for a sermon, in writing, in everything, which is quite astonishing.
Always respond to it immediately, such a call to prayer must never be regarded as a distraction; and thank God if it happens to you frequently.
D. Martyn Lloyd-Jones, from Preaching and Preachers, p.170-171