Just remember:

1. On your SIDE, there is no such thing as NOC - No Objection Certificate to keep your husband under your sponsorship. Don't make any letter and that's it. Your husband will be under your sponsorship until the duration of his visa.

2. On your SIDE, there is only a NOC - No Objection Certificate to release you husband from your sponsorship to a particular sponsor.

So the one who has to issue a NOC - No Objection Certificate is the prospective employer of your husband, stating that they have no objection that your husband stays UNDER YOUR SPONSORSHIP while working with them.