Haste?

new to tanking as a paladin main spec is holy, was just wondering y u want so miuch haste

Haste will increase your generation of Holy Power which allows more frequent use of your abilities and is of particular value for Seraphim if you choose that talent, though if new to tanking you should probably take Holy Shield. It also helps with threat generation as a new tank which can be an issue when you are paired with better geared tanks.

Taking Empowered Seals and staying in Seal of Righteousness is miles ahead in aggro generation, plus it makes reaching the haste softcap (25% before Raid buffs and Empowered Seals) trivial. As for the value of haste, it also means more sacred shields, a substantial defensive benefit, together with many more Shield of the Righteous cast and uptime.

For example, in one fight, I managed (at Kilrogg) effectively 100% uptime of Shield of the Righteousness, meaning constant >40% damage reduce.

https://www.warcraftlogs.com/reports/Gm ... s&source=6

Extermi

Mostly due to giving you more Shield of the Righteous coverage. Your holy power generators come off CD faster due to http://www.wowhead.com/spell=25956/sanctity-of-battle and we get a bonus on any haste on our gear from http://www.wowhead.com/spell=165375/sacred-duty