Heavy Metal
Daf yomi learners finished Masechta Middos this week. Middos discusses the measurements of the Beis HaMikdash and its utensils. Seemingly there is little relevance to us nowadays in knowing these historical facts.
Beis HaMikdash
Iron Touching the Mizbeach in the Gemara
Why an iron implement that touches a stone of the Mizbeach disqualifies it, since iron can shorten life while the Altar lengthens it.