It would seem beautiful to know that all we had to do was listen to the tops of the poplar trees. God calls us all to faith, not sight. Even in this text. What did David do? He inquired of God about the attacking Philistine army. May that direct us in all our ways to acknowledge Him who directs our paths, our every step. "In distress, fly to Him; when wronged appeal to Him; and when we know not what to do, ask counsel at His oracles to put ourselves under His direction and beg of Him to show us the right way." Matthew Henry.
And may the sound in the tops of the going in the tops of the mulberry trees, direct us "to attend to God's motions both in His Providence and in the influences of His Spirit."