But Daniel 'purposed in his heart'— he made up his mind that come what may, he was not going to eat the food from the King's table, nor was he going to drink his alcoholic wine!

9, 10 Now God had brought Daniel into favour and tender love with the prince of the eunuchs.  And the prince of the eunuchs said unto Daniel, I fear my lord the king, who hath appointed your meat and your drink: for why should he see your faces worse liking than the children which are of your sort? then shall ye make me endanger my head to the king. 

He spoke to Melzar, the man that had been put in charge of himself and his three friends.

 

11-13 Then said Daniel to Melzar, whom the prince of the eunuchs had set over Daniel, Hananiah, Mishael, and Azariah,  Prove thy servants, I beseech thee, ten days; and let them give us pulse to eat, and water to drink. Then let our countenances be looked upon before thee, and the countenance of the children that eat of the portion of the king's meat: and as thou seest, deal with thy servants.

He asked that they be allowed to have 'pulse' —fruits and vegetables for their diet and plain water to drink. 

Now the Bible tells us that God had caused the Prince of the Eunuchs that had charge over Daniel to be very fond of him. 

BUT this request seemed IMPOSSIBLE!

"What do you think will happen to me, if the King sees you not looking as ruddy and healthy as the rest of the young men? Why— he will have my head!!"