18-64

सर्व गुह्यतमम् भूयः शृणु मे परमम् वचः ।
इष्टोऽसि मे धृढम् इति ततो वक्ष्यामि ते हितम् ॥ ६४ ॥

sarva guhyatamam bhUyaH zRNu me paramam vacaH |
iSTo'si me dhRDham iti tato vakSyAmi te hitam || 64 ||

शृणु [zRNu] Listen भूयः [bhUyaH] once more परमम् [paramam] to this supreme वचः [vacaH] directive मे [me] of mine, गुह्यतमम् [guhyatamam] the most subtle सर्व [sarva] of all. इति वक्ष्यामि [iti vakSyAmi] I state this ते हितम् [te hitam] for your benefit, ततो [tato] since धृढम् इष्टोऽसि [dhRDham iSTo'si] you are very dear मे [me] to Me.

Among all these secrets, devotion is superior.

Even earlier, it was referred to as ‘extremely concealed’ in 9-1: ‘You are not jealous. I will tell you this knowledge, which is extremely concealed’.

Listen to that instruction once again from Me. It’s My supreme and final directive. I state this for your benefit, since you are very dear to Me.