Which two signs in John's Gospel are associated with sin and with a pool?

Les explains that after the first two miracles in Cana, Jesus went up to Jerusalem, and by the sheep market there was a pool called Bethesda with five porches. Among the signs, the impotent man and the blind man are distinct because they are associated with sin, and both are associated with a pool. Les notes that none of the other signs mention sin; they show need, but they do not necessarily reveal sin. The pool, as water, indicated a need for cleansing, which is why there was so much washing in Israel’s religious ritual. The impotent man had an infirmity thirty-eight years, which recalls Israel’s wilderness period—really thirty-eight years, close to forty—and forty in God’s dealing with Israel is indicated as a time of testing.