Mark 11:23-24
11:23 I tell you the truth, 1 if someone says to this mountain, ‘Be lifted up and thrown into the sea,’ and does not doubt in his heart but believes that what he says will happen, it will be done for him.
11:24 For this reason I tell you, whatever you pray and ask for, believe that you have received it, and it will be yours.
1 tn Grk “Truly (ἀμήν, amhn), I say to you.”