In Peurifoy et al. v. Commissioner of Internal Revenue, the Supreme Court ruled on whether payments made by a company to its employees for expenses incurred while traveling and living away from home were deductible as business expenses or should be considered taxable income for the employees. The court held that these payments constituted income to the workers and thus were subject to tax under Section 22(a) of the Internal Revenue Code, which defines gross income as "all income from whatever source derived." This decision was based on an interpretation that such reimbursements are not exempted by Section 23(a)(1)(A), which allows deductions for ordinary and necessary business expenses paid during the taxable year in carrying on any trade or business. The ruling clarified that reimbursement amounts exceeding what is deemed reasonable can be taxed, emphasizing employers' responsibility in ensuring fair compensation without exploiting tax benefits.

In the dissenting opinion for Peurifoy et al. v. Commissioner of Internal Revenue, Justice Brennan disagreed with the majority's decision to uphold a tax court ruling that disallowed deductions claimed by taxpayers who had entered into mining lease agreements. He argued that these leases were not "true" leases but rather constituted an advance sale of mineral rights, and thus should be treated as capital gains instead of ordinary income. The justice contended that this interpretation was more consistent with both the language and intent of relevant tax laws, which aim to encourage investment in natural resources exploration and development by providing favorable tax treatment for such activities. Furthermore, he criticized the majority's reliance on factual distinctions between different types of lease arrangements as arbitrary and inconsistent with established legal principles governing taxation issues.