The Tenant may move furniture, fixtures, and equipment into and out of the Premises [only] during nonbusiness hours unless Landlord gives approval otherwise.
[Prompted by D.C.’s comment I moved only, but that’s unrelated to the topic of this post.] Omitting only could result in confusion, because the tenant could argue that it may also move stuff during business hours. Here’s what MSCD 3.190 says:
A grant of discretion to do one thing doesn’t necessarily equal a prohibition against doing other things. If a mother tells her son he may play video games, it wouldn’t necessarily follow that she’s forbidding him from engaging in any alternative activity.
As explained in MSCD, you could invoke “the expectation of relevance” in arguing that the tenant may not move stuff during business hours. But as a drafter I’m not interested in having an argument at my disposal in a fight; I want to avoid fights. If you want discretion to be limited, use only.
Now consider these two examples, the first real, the second invented:
The Carrier shall transport all loads tendered to it [only] under its own authority, on equipment owned or leased by it, and use employees or independent contractors under contract with it.
Acme shall pay the Purchase Price [only] in Polish złotys.
Language of discretion leaves open alternatives; language of obligation might not. In language of obligation that is all-encompassing, only is redundant. By “all-compassing,” I meant that it applies to the totality of whatever is at issue. Acme shall give peanuts to Dumbo means that Acme would be allowed to give some peanuts to Dumbo and devote other peanuts to other purposes. To make it all-encompassing, you’d have to say all peanuts or only to Dumbo.
The two examples above are all-encompassing without the only. In the first, that’s achieved by both all and tendered to it; in the second, that’s achieved by the reference to only one item, the Purchase Price. So omit the only.
Incidentally, this was brought to light thanks to my work with LegalSifter, in particular discussions regarding the specifications for a particular “sifter”—a piece of software that looks for a particular issue. Aside from the other merits of LegalSifter, it forces me to keep exploring ever more subtle nuances of contracts prose.