An-Nahl 16:94

Wala tattakhithoo aymanakumdakhalan baynakum fatazilla qadamun baAAda thubootiha watathooqooassoo-a bima sadadtum AAan sabeeli Allahiwalakum AAathabun AAatheem

And do not take your oaths as [means of] deceit between you, lest a foot slip after it was [once] firm, and you would taste evil [in this world] for what [people] you diverted from the way of Allāh, and you would have [in the Hereafter] a great punishment.

Do not make your oaths a means of mischief among yourselves, lest a foot should slip after it is firmly placed, and you taste evil consequences for your having prevented (others) from the path of Allah, and you incur a great punishment.