Hindu scriptural sources don't treat Punjab ie NorthWest as part of the broader Hindu world - they explicitly define it as outsidethe boundaries of Āryāvarta (the land of the Āryas).
Śatapatha Brāhmaṇa 9.3.1.24 speaks in directly negative terms about "the inhabitants of the region of the seven rivers that flow westward, i.e. the Punjab," calling them ruffians and barbarians whom one should avoid.
The Dharmasūtras (Baudhāyana 1.1.2.9, Vāsiṣṭha 1.8-9) define Āryāvarta's western boundary at the spot where the Sarasvatī disappears - around modern Patiala - placing Punjab at or beyond the edge of ritually pure territory.
Manusmṛti 10.43-44 lists the Kambojas, Yavanas, and Śākas (all Punjab/northwest-associated groups) among degraded peoples who fell from proper status "due to the absence of Brahmins among them."
There's even the well-known rule that crossing certain rivers (like the Yamuna westward) required śuddhi (purification) upon return - Punjab was treated as ritually contaminating territory.