Waannahu kana rijalun mina al-insi yaAAoothoona birijalin mina aljinni fazadoohum rahaqa (surah Jinn: 6)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(72:6) and that 'some from among the humans used to seek protection of some among the jinn, and thus they increased the arrogance *7 of the jinn';

Wa annahoo kaana rijaa lum minal insi ya`oozoona birijaalim minal jinni fazaa doohum rahaqaa

*7) Ibn `Abbas says that in the pre-lslamic days of ignorance when the Arabs had to spend a night in some uninhabited, desolate valley, they would shout out: "We seek refuge of the jinn, who is owner of this valley." In other traditions of the pre-Islamic ignorance also the same thing has been reported frequently. For example, if in a place they ran short of water and fodder, the wandering Bedouins would send one of their men to some other place to see if water and fodder were available; and when they reached the new site under his direction, they would shout out before they halted to pitch the camp: "We seek refuge of the sustainer of this valley so that we may live here in peace from every calamity." They believed that every un-inhabited place was under the control of one or another jinn, and if someone stayed there without seeking his refuge, the jinn would either himself trouble the settlers, or would let others trouble them. These believing jinn are referring to this very thing. They meant that when man, the vicegerent of the earth, started fearing them without any reason, and started seeking their refuge instead of God's, it caused their people to become even more arrogant, haughty and wicked, and they became even more fearless and bold in adopting error and disbelief.