सैन्धवस्य घनो यद्वज्जलयोगाज्जलं भवेत् ।स्वात्मयोगात्तथा बुद्धिरात्मैव ब्रह्मवेदिनः ॥ ५१ ॥
In plain words
A lump of salt dissolves into water until no separateness remains. So too, for the knower of Brahman, the intellect resting wholly in the Self loses its imagined separateness and is known as the Self alone.
Close to the Sanskrit
Just as a solid lump of salt, through contact with water, becomes water, so through union with one's own Self the intellect of the knower of Brahman becomes the Self itself.