Ephesians 6:18-19:

Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;
And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel,

See also:

Preparing to Minister Healing
Healing Preachers WILL Be Persecuted
Objection: God Wants You to Bring SUPPLICATIONS and REQUESTS to HIM (Philippians 4:6), Not to “Take Authority” Yourself