John Wesley on Luke 4:25

When the heaven was shut up three years and six months - Such a proof had they that God had sent him. In 1Kings 18:1, it is said, The word of the Lord came to Elijah in the third year: namely, reckoning not from the beginning of the drought, but from the time when he began to sojourn with the widow of Sarepta. A year of drought had preceded this, while he dwelt at the brook Cherith. So that the whole time of the drought was (as St. James likewise observes) three years and six months. 1Ki 17:19; 18:44.