N.Y. Jud. Law § 141
At the request of the presiding justice of any judicial department, the presiding justice of any of the other departments of the state may consent to the assignment from among the trial justices of any judicial district in his department, of such justices as in his opinion may be spared from said district, without prejudice to the work or interests of such district, to hold trial or special terms in the department from whence the request may come.
No consent shall be given hereunder to the assignment of a justice or justices from any district that will not leave at all times at least two trial justices in such district; and no allowance given by any statute for services, or expenses, rendered, or incurred by any trial justice for sitting in the first or second departments shall be paid, unless assigned with such consent as hereinbefore provided.
N.Y. Jud. Law § 141