According to Catholicculture.org, the first reading is taken from the book of Exodus 17:8-13, the second reading is from the second letter of Paul to Timothy 3:14, 4:2. St. Paul, while the Gospel is from St. Luke 18:1-8.
Luke 18:1-8 (American Standard Version (ASV)) The Parable of the Persistent Widow :
And he spake a parable unto them to the end that they ought always to pray, and not to faint;
(2) saying, There was in a city a judge, who feared not God, and regarded not man:
(3) and there was a widow in that city; and she came oft unto him, saying, Avenge me of mine adversary.
(4) And he would not for a while: but afterward he said within himself, Though I fear not God, nor regard man;
(5) yet because this widow troubleth me, I will avenge her, lest she wear me out by her continual coming.
(6) And the Lord said, Hear what the unrighteous judge saith.
(7) And shall not God avenge his elect, that cry to him day and night, and yet he is longsuffering over them?
(8) I say unto you, that he will avenge them speedily. Nevertheless, when the Son of man cometh, shall he find faith on the earth?
There are a number of ways we can study the Bible, but one of the most effective and simple approaches to reading and understanding God’s Word, according to BibleStudyTools.com, involves three simple steps.