When the sun set for sure, then start from the holy Arafah’s ground towards Muzdalafah.  Throughout the distance, keep reciting salutations and blessings and saying labbaik.  yesterday at the ground of holy Arafah rights of Allah (huqooq-ullah were forgiven, and today here the rights of (servants) others (hoqooq-ul-ibaad) are promised to be forgiven. (Bahar-e-Shariyat, Volume 1, Part 6, pages 1131, 1133)