The ancient Jewish rabbinic schools had rules on how you could interpret Scripture, basically logical and rhetorical rules about making a valid conclusion from what was given. One of the key forms of argument is marked by the use of the phrase, "How much more". It's known in Latin by the name a fortiori or a minori ad majus (or ad majore ad minus, if the logic runs the opposite direction). This form of reasoning, applied to Scripture, is said to trace back at least to the school of Hillel, so it was likely accepted and in place as a rule of Scriptural interpretation before Jesus' birth. As a rule of reasoning, it goes back further still.
In Scripture, we see that not only Moses and Paul but also Jesus himself accepted and used this form of reasoning. (How much more, then, should we!) Here are a few examples of this form of reasoning applied within Scripture through the ages:
- While I am yet alive with you this day, you have been rebellious against the LORD, and how much more after my death? (Deut 31:27)
- The son of my own body seeks my life: how much more may this Benjamite? (2 Sa 16:11)
- He puts no trust in his saints; even the heavens are not clean in his sight. How much more filthy is man, who drinks iniquity like water? (Job 15:15-16)
- The sacrifice of the wicked is an abomination; how much more when he brings it with a wicked mind? (Proverbs 21:27)
- If you, being evil, know how to give good gifts to your children, how much more shall your heavenly Father give good things to those who ask him? (Matt 7:11)
- If God so clothes the grass which is today in the field and tomorrow cast into the oven, how much more will he clothe you, O you of little faith? (Luke 12:28)
- Do you not know that we shall judge angels? How much more things that pertain to this life? (1 Corinthians 6:3)
- If the blood of bulls and goats and the ashes of a heifer sprinkled on the unclean sanctifies it to the purification of the flesh, how much more shall the blood of Christ? (Hebrews 9:13-14)
At times it is implicit, as when Jesus teaches us that the sparrows are watched over and cared for by God, and we are worth more than many sparrows. He invites us to conclude with the same type of logic: how much more are we watched over and cared for by God.
There are more examples in Scripture than I have shown here. A search for "how much more" in your favorite Scripture search engine will show that this was a widely used approach to drawing conclusions. It was well-accepted by those who founded our faith. We see Jesus applying it and have reason to believe he expected us to be able to apply it as well. Next I'll show some of the implications of using it to help us understand his teachings.