Matthew 3:10

3:10 Even now the ax is laid at ¹  the root of the trees, and every tree that does not produce good fruit will be cut down and thrown into the fire.

Matthew 27:42

27:42 “He saved others, but he cannot save himself! He is the king of Israel! If he comes down ²  now from the cross, we will believe in him!

[3:10]  ¹ sn Laid at the root. That is, placed and aimed, ready to begin cutting.

[27:42]  ² tn Here the aorist imperative καταβάτω (katabatw) has been translated as a conditional imperative. This fits the pattern of other conditional imperatives (imperative + καί + future indicative) outlined by ExSyn 489.