Here are all the scriptures that mention fasting

1Ki 21:9 In those letters she wrote: "Proclaim a day of fasting and seat Naboth in a prominent place among the people.

Ne 9:1 On the twenty-fourth day of the same month, the Israelites gathered together, fasting and wearing sackcloth and having dust on E'S their heads.

4:3 In every province to which the edict and order of the king came, there was great mourning among the Jews, with fasting, weeping and wailing. Many lay in sackcloth and ashes.

Es 9:31 to establish these days of Purim at their designated times, as Mordecai the Jew and Queen Esther had decreed for them, and as they had established for themselves and their descendants in regard to their times of fasting and lamentation.

Ps 35:13 Yet when they were ill, I put on sackcloth and humbled myself with fasting. When my prayers returned to me unanswered,

Ps 109:24 My knees give way from fasting; my body is thin and gaunt.

Isa 58:3 `Why have we fasted,' they say, `and you have not seen it? Why have we humbled ourselves, and you have not noticed?' "Yet on the day of your fasting, you do as you please and exploit all your workers.

Isa 58:4 Your fasting ends in quarrelling and strife, and in striking each other with wicked fists. You cannot fast as you do today and expect your voice to be heard on high.

Isa 58:6 "Is not this the kind of fasting I have chosen: to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke?

Jer 36:6 So you go to the house of the LORD on a day of fasting and read to the people from the scroll the words of the LORD that you wrote as I dictated. Read them to all the people of Judah who come in from their towns.

Jer 36:9 In the ninth month of the fifth year of Jehoiakim son of Josiah king of Judah, a time of fasting before the LORD was proclaimed for all the people in Jerusalem and those who had come from the towns of Judah.

Da 9:3 So I turned to the Lord God and pleaded with him in prayer and petition, in fasting, and in sackcloth and ashes.

Joe 2:12 "Even now," declares the LORD, "return to me with all your heart, with fasting and weeping and mourning."

Mt 4:2 After fasting for forty days and forty nights, he was hungry.

Mt 6:16 "When you fast, do not look sombre as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full.

Mt 6:18 so that it will not be obvious to men that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.

Mr 2:18 Now John's disciples and the Pharisees were fasting. Some people came and asked Jesus, "How is it that John's disciples and the disciples of the Pharisees are fasting, but yours are not?"

Mr 9:29 He replied, "This kind can come out only by prayer."

Lu 2:37 and then was a widow until she was eighty-four. She never left the temple but worshipped night and day, fasting and praying.

Ac 13:2 While they were worshipping the Lord and fasting, the Holy Spirit said, "Set apart for me Barnabas and Saul for the work to which I have called them."

Ac 14:23 Paul and Barnabas appointed elders for them in each church and, with prayer and fasting, committed them to the Lord, in whom they had put their trust.