In plain words
But because we let prāṇa roam loose, with this body like a water bubble and with this fickle mind, our whole life is turning into a brute's life. This first verse has been setting out the principle of the annamaya, manomaya and prāṇamaya. Without food, the body cannot live. Without the body, we cannot search out the mind. Without the mind itself, we cannot recognise prāṇa. So, since the vijñānamaya and ānandamaya both rest on the annamaya, manomaya and prāṇamaya, we strive for the vijñānamaya and ānandamaya. The annamaya, manomaya and prāṇamaya are impermanent and of no value, and the vijñānamaya and ānandamaya are supremely important higher principles; yet these rest only on the worthless annamaya, manomaya and prāṇamaya. We must look after the annamaya, manomaya and prāṇamaya in order to experience the vijñānamaya and ānandamaya. Here is a small example of this. When we have precious jewels and diamonds in our home, we keep them, precious as they are, in a worthless iron box. Today we think it foolish to keep precious things in this worthless box. Our body itself is a useless, worthless box. In such a worthless box God has hidden the precious diamonds of the vijñānamaya and ānandamaya. Judging by our own needs, we think, somewhat laughably, that it is not proper for God to put such precious things in a worthless body. It is because God is the very form of Buddhi, and because His many powers of reflection merge in His will, that all He creates, every bit of it, is fruitful; He never resolves in the least to create anything fruitless. If we try to keep precious gold jewellery in a precious gold box, nobody looks at the jewels inside: thinking the box alone is enough, they set about stealing it. So it is natural to keep precious things in worthless containers.