Why do we tie the Lulav? Why not let the fronds spread out?
I know that there is symbolism derived from the binding, but is it actually required to bind the Lulav? What about binding the Hadasim and 'Aravoth to it? If the rings fall off or I don't have time to tie them, am I Yotzei the Mitzvah?
The Mordechai (Moed 749) quotes the Raavan who writes that the custom around him was to make three knots on the Lulav, symbolizing the three patriarchs. This custom is recorded by Rama in OC 651:1. The Taz there notes that this is not stronger than a custom and that the knots should be made such that the leaves can still rattle somewhat. The Taz also opines that the three knots include the main knot which binds the Aravot and Hadasim to the Lulav, but the Elya Rabba there thinks that there should be three knots independent of the main knot.