In Hindu conventions, one invariably finds customs and rituals. On the surface, they seem to be innocuous, but dig deeper, and you will find that there is a reason behind everything. Similarly, we’re trying to figure out whether there’s a purpose for the coconut and banana offers, and there is.
Coconut and bananas are the only two fruits which are considered to be “Sacred fruits”. The rest of the fruits are contaminated (fruits that have been half eaten), which means they have seeds and may proliferate!
Coconut is referred to as Shri Phal or a divine fruit or God’s fruit. But in the case of a coconut, if you eat its flesh and throw out its outer shell, nothing will grow out of it. If you want to grow a coconut tree, you have to sow the entire coconut itself. The outer shell of a coconut is the Ahamkara or ego, which one has to break.
Once the ego is shed, the mind will be as pure as the white tender coconut inside. The Bhavaavesha or Bhakthi will pour like sweet water in it. The 3 eyes on the top is described as Satwa, Raja and Tama or Past , Present and Future or Sthoola, Sukshma and Karana Sareera or body etc.
Additionally, bananas are in the same boat as well. Nothing will sprout out of a banana if you eat it and toss the skin out. A banana tree is grown on its own when a banana plant starts producing fruits.
Our ancestors discovered this reality a long ago and they had turned it into a custom which is still followed rigorously today!