Bhagavad Gita Chapter 4 Verse 3

Gita 4.3

सः, एव, अयम्, मया, ते, अद्य, योगः, प्रोक्तः, पुरातनः,
भक्तः, असि, मे, सखा, च, इति, रहस्यम्, हि, एतत्, उत्तमम्।।3।।

Gita 4.3

SaH, ev, ayam’, mya, te, adhya, yogH, proktH, puraatanH,
BhaktH, asi, me, sakhaa, ch, iti, rahsyam’, hi, etat’, uttamm’ ||3||

Translation: You (me) my (bhaktH) devotee (ch) and/as well as (sakhaa) friend (asi) is (iti) therefore (saH) that very (ayam’) this (puraatanH) ancient (ev) actual (yogH) way of bhakti (adhya) old (mya) I (te) to you (proktH) said (hi) because (etat’) this (uttamm’) supreme (rahsyam’) secret i.e. is worthy of being kept a secret. (3)

Gita 4.3: You are my devotee as well as friend. Therefore I have said that same this ancient, old and actual way of bhakti to you because this is a supreme secret i.e this matter is worthy of being kept a secret.