Dictionary.com defines the word incubate as
Joshua 1:8 says, “This Book of the Law shall not depart from your mouth, but you shall meditate in it day and night, that you may observe to do according to all that is written in it. For then you will make your way prosperous, and then you will have good success.”
It’s the same with meditating on the promises of God. When you’re believing for manifestation of a promise given, you just can’t entertain other opposing thoughts or opinions. You must keep your focus on the promise, even when it doesn’t feel like anything is happening. Even when you don’t see any change, you must believe that the God who spoke it, is well able to do what He said He would do. Your part is only to believe it with all your heart, mind and soul.
Philippians 4:8 says it like this; Finally, brethren, whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is any virtue and if there is anything praiseworthy—meditate on these things.
When a chicken sits on the egg to hatch it, there’s a natural progression to the process. As soon as the chick starts to peck it’s way out of the egg, there’s no longer a need to sit on it. Watch for signs of progress on your promise, but until you know in your spirit that it’s coming, continue to meditate and incubate your promise.