Reading through Testimonies to Ministers and Gospel Workers I found this gem. It talks about the experience of the disciples in praying for the Holy Spirit. The gift requires an experience on our parts forged in prayer.

Especially should men pray that the Lord will choose His agents, and baptize His missionaries with the Holy Spirit. For ten days the disciples prayed before the Pentecostal blessing came. It required all that time to bring them to an understanding of what it meant to offer effectual prayer, drawing nearer and nearer to God, confessing their sins, humbling their hearts before God, and by faith beholding Jesus, and becoming changed into His image. When the blessing did come, it filled all the place where they were assembled, and, endowed with power, they went forth to do effectual work for the Master. – {Testimonies to Ministers and Gospel Workers 170.1}